DD- Virology of RSV Flashcards
RSV
Human respiratory syncytial virus (RSV)
RSV
a virus that causes respiratory tract infections. It is a major cause of lower respiratory tract infections and hospital visits during infancy and childhood.
RSV Epidemiology
Large particle droplet spread
Very high (40-60%) attack rate children < 2 years
Most serious illness in very young, specific high-risk populations
is there an rsv vaccine?
no
RSV structure- ________ family
paramyxoviridae
RSV structure genome
Single-stranded, nonsegmented RNA virus
RSV
Fusion of viral envelope to host cell
Fusion of membranes of infected cells to each other “syncytia”
F protein
RSV
Initial binding of virus to host cell
G protein:
RSV subtypes
A and B
A causes most disease
RSV Pathophysiology- Invades:
conjunctiva/nasopharynx
RSV causes severe damage to the epithelium and _________apparatus
bronchiolar ciliary
*Results in collection of fluid in the bronchioles and alveoli
RSV Pathophysiology _________incubation period
3-5 day
Clinical Picture or RSV
Respiratory distress, wheeze/rhonchi, hypoxia, copious secretions: Bronchiolitis
RSV causes severe damage to the _________and bronchiolar ciliary apparatus
epithelium
*Results in collection of fluid in the bronchioles and alveoli
Testing for RSV
Cell culture – takes more time
Direct antigen detection (rapid test) – not very sensitive/accurate
Nucleic acid/Genomic amplification (PCR) – most accurate and quick in many
places
do people get recurrent infections of RSV?
Yes
RSV _______ like influenza to avoid immune system
“drifts”
RSV has been associated with _________later in life, but whether it causes it is unclear
wheezing & asthma
Is there an RSV vaccine?
no
vaccine attempts made disease worse
RSV vaccine recipients were not protected against disease and they had worse RSV disease when they got infected with RSV.
Hypothesized that serum antibody without local respiratory antibody may _________disease.
worsen
RSV immunoprophylaxis with Palivizumab (Respigam)
Respigam is a human pooled antibody with high RSV titers, shown to have decrease in disease severity and hospitalization
A mouse monoclonal anti-RSV antibody was developed
Palavisumab
Synagis
RSV vaccine recipients were not protected against disease and they had _____RSV disease when they got infected with RSV.
Hypothesized that serum antibody without local respiratory antibody may _________disease.
worse
worsen
Antibody/immune protection is _________for infection, but previous infection may prevent more severe disease
incomplete
